As an electrophotographic photosensitive member installed in an electrophotographic apparatus, organic electrophotographic photosensitive members containing an organic photoconductive substance (charge-generating substance) (hereinafter, may be referred to as “electrophotographic photosensitive members”) have been used. In the electrophotographic process, various members, such as a developer, a charging member, a cleaning blade, paper, and a transfer member, (hereinafter, may also be referred to as “contact members and the like”) come into contact with the surface of an electrophotographic photosensitive member. Therefore, in the electrophotographic photosensitive member, it is required to reduce the occurrence of image degradation caused by contact stress with these contact members and the like. In particular, as the durability of electrophotographic photosensitive members has been improved in recent years, the electrophotographic photosensitive members have been required to maintain the effect of reducing image degradation caused by contact stress.
Regarding continuous reduction of contact stress, PTL 1 has proposed a method in which, using a siloxane resin having a siloxane structure incorporated into its molecular chain, a matrix-domain structure is formed in a surface layer. The proposal shows that, by using a polyester resin into which a specific siloxane structure is incorporated, it is possible to achieve both continuous reduction of contact stress and potential stability (suppression of variation) when the electrophotographic photosensitive member is repeatedly used.
On the other hand, a proposal has been made in which a siloxane-modified resin having a siloxane structure in its molecular chain is incorporated into a surface layer of an electrophotographic photosensitive member. PTL 2 and PTL 3 each have proposed an electrophotographic photosensitive member containing a polycarbonate resin into which a siloxane structure having a specific structure is incorporated, and have reported effects of improvement in resistance to solvent cracking due to a mold-releasing action and lubricity of the surface of the photosensitive member at the beginning of use.